1. Field of the Invention
The invention relates to a control apparatus for a vehicle, and a method of controlling a vehicle. More specifically, the invention relates to a technology in which the amount of air taken into an engine is increased during a torque phase when an automatic transmission upshifts.
2. Description of the Related Art
When an automatic transmission upshifts, a driving force decreases during a torque phase, and then the driving force increases and a shock occurs when the torque phase ends and an inertia phase starts. To suppress the shock when the automatic transmission shifts, the technology in which the torque is boosted during the torque phase is proposed.
Japanese Patent Application Publication No. 5-263911 (JP-A-5-263911) describes a shift shock reduction control apparatus for an automatic transmission, in a system that includes at least one electronic control unit that electronically controls an engine and the automatic transmission. When an instruction for starting a gear shift is output, the shift shock reduction control apparatus described in the above publication starts to gradually retard an ignition timing. The shift shock reduction control apparatus advances the ignition timing to a normal timing at a given time constant after the torque phase starts, and retards the ignition timing by a given value after the inertia phase starts. When the inertia phase ends, the shift shock reduction control apparatus advances the ignition timing to the normal timing. Further, when the torque phase starts, the shift shock reduction control apparatus increases the amount of air by a given amount using an engine intake-air amount correction control portion so that the amount of fuel is automatically increased, and engine torque is increased. When the inertia phase starts, the shift shock reduction control apparatus stops increasing the amount of air. When the inertia phase ends, the shift shock reduction control apparatus increases again the amount of air by a given amount in a stepwise manner. As time elapses, the shift shock reduction control apparatus gradually decreases the amount of air.
With the shift shock reduction control apparatus described in the above publication, it is possible to minimize the possibility that the torque is decreased during the torque phase. Accordingly, it is possible to reduce the possibility that the torque is sharply increased during the inertia phase. As a result, it is possible to reduce an amount by which the torque changes at the end of the inertia phase. Thus, the control is executed to minimize the shift shock.
The shift shock reduction control apparatus described in the above publication retards the ignition timing and stops increasing the amount of air after the inertia phase starts. Therefore, the engine torque may be sharply decreased during the inertia phase. In this case, driving force is sharply decreased, and a driver feels that a vehicle is decelerated during the inertia phase. This deteriorates driveability.